Effects of infrared treatment of chia seeds on mucilage yield and mucilage properties.

The aim of this study was to investigate effects of infrared treatment (700 W,900 W,1100 W-25 and 50 min) of chia seeds on mucilage yield and mucilage properties. Infrared treatment (except 1100 W-50 min) caused a significant (p < 0.05) increase in mucilage yield, with the highest value (6.99%) obtained at 1100 W-25 min. Infrared treatment at 700 W did not cause a significant change in total dietary fiber content, while 900 W and 1100 W led to significant decrease. Infrared treatment of chia caused some changes in FTIR spectra (especially at 2370-2363 cm-1). DSC thermograms showed similar thermal transitions as reported in literature. Higher enthalpy values showed more energy requirement for water removal, which may result in improved food stability. Higher crystallinity in XRD patterns indicated that infrared treatment may enhance the mechanical properties and thermal stability. Infrared treatment up to 900 W-25 min did not cause a significant decrease in water holding capacity. Infrared treatment at 700 W and 900 W caused a significant increase in emulsion activity and stability. The viscosity values of M2 and M3 samples at both concentrations (1 and 2%) were higher compared to the control. Mucilage samples obtained from chia infrared-treated at 700 W and 900 W exhibited higher water holding capacity (except 900 W-50 min) and improved emulsion properties, with the highest emulsion capacity and stability obtained for 900 W for 50 min. Improvements in these properties and mucilage yield (from 6.01% (control) to 6.46% (700 W) and 6.68% (900 W)) suggest that infrared treatment of chia seeds at 700 W and 900 W may be promising for its application as hydrogels, film-coating or emulsifying agents.